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81.
Narang Rajan Chandrasekaran Kannan Gupta Arvind 《Journal of Failure Analysis and Prevention》2017,17(3):595-601
Journal of Failure Analysis and Prevention - Magnetic flux leakage (MFL) principle is widely used in detecting defects in cross-country pipelines. The tools based on the MFL techniques termed as... 相似文献
82.
Devendrasinh Darbar M.R. Anilkumar Vijayaraghavan Rajagopalan Indranil Bhattacharya Hendry Izaac Elim T. Ramakrishnappa F.I. Ezema Rajan Jose M.V. Reddy 《Ceramics International》2018,44(5):4630-4639
Optimization of electrodes for charge storage with appropriate processing conditions places significant challenges in the developments for high performance charge storage devices. In this article, metal cobaltite spinels of formula MCo2O4 (where M = Mn, Zn, Fe, Ni and Co) are synthesized by oxalate decomposition method followed by calcination at three typical temperatures, viz. 350, 550, and 750 °C and examined their performance variation when used as anodes in lithium ion batteries. Phase and structure of the materials are studied by powder x-ray diffraction (XRD) technique. Single phase MnCo2O4,ZnCo2O4 and Co3O4 are obtained for all different temperatures 350 °C, 550 °C and 750 °C; whereas FeCo2O4 and NiCo2O4 contained their constituent binary phases even after repeated calcination. Morphologies of the materials are studied via scanning electron microscopy (SEM): needle-shaped particles of MnCo2O4 and ZnCo2O4, submicron sized particles of FeCo2O4 and agglomerated submicron particle of NiCo2O4 are observed. Galvanostatic cycling has been conducted in the voltage range 0.005–3.0 V vs. Li at a current density of 60 mA g?1 up to 50 cycles to study their Li storage capabilities. Highest observed charge capacities are: MnCo2O4 – 365 mA h g?1 (750 °C); ZnCo2O4 – 516 mA h g?1 (550 °C); FeCo2O4 – 480 mA h g?1 (550 °C); NiCo2O4 – 384 mA h g?1 (750 °C); and Co3O4 – 675 mA h g?1 (350 °C). The Co3O4 showed the highest reversible capacity of 675 mA h g?1; the NiO present in NiCo2O4 acts as a buffer layer that results in improved cycling stability; the ZnCo2O4 with long needle-like shows good cycling stability. 相似文献
83.
Electrochemical migration (ECM) of tin can result in the growth of a metal deposit with a dendritic structure from cathode to anode. In electronics, such growth can lead to short circuit of biased electrodes, potentially leading to intermittent or complete failure of an electronic device. In this paper, mechanistic aspects of ECM of tin are discussed in detail, using experimental results on ECM of tin in various environments and varying potential bias. Results on the formation of local pH changes by the electrodes and experiments observations are combined with thermodynamic stability of tin species as depicted in the Pourbaix diagram. 相似文献
84.
Rajan Alex 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2006,10(7):618-622
In this paper, a new kind of fuzzy regression model suggested by the author in papers [1] and [2] will be restated more clearly.
Then a consistency between the new fuzzy regression modeling and fuzzy inference modeling will be presented, showing its added
advantage for application problems. Based on the consistency, a method for combining fuzzy regression and fuzzy inference
will be introduced in this paper. This will serve as the starting point for applying the two kinds of information resources,
quantitative and qualitative information resources, simultaneously in practical prediction problems.
This work was supported by a Research Enhancement Grant, WTAMU, 2003. 相似文献
85.
86.
87.
The devastating consequences of aerosol/mist explosions have been widely documented, and there are currently efforts to understand the mechanisms of formation and explosion of aerosols. Heat-transfer fluids (HTFs) are particularly susceptible to these hazards, because they are utilized under high pressures and below their flash points, making them more prone to leaking as aerosols. In fact, there is a critical need during design stages for a perception of explosion risks associated with the selection of HTFs. This paper discusses a novel scheme to integrate the knowledge of HTF aerosol formation from leaks in process equipment into the selection of HTFs during the design process. Hazards of aerosols formed from leaks are classified qualitatively using process pressure and droplet sizes. 相似文献
88.
M.G. Hemanath C. MeikandamurthyV. Ramakrishnan K.K. RajanM. Rajan G. Vaidyanathan 《Annals of Nuclear Energy》2007
In the pool type fast reactors the roof structure is penetrated by a number of pumps and heat exchangers that are cylindrical in shape. Sandwiched between the free surface of sodium and the roof structure, is stagnant argon gas, which can flow in the annular space between the components and roof structure, as a thermosyphon. These thermosyphons not only transport heat from sodium to roof structure, but also result in cellular convection in vertical annuli resulting in circumferential temperature asymmetry of the penetrating components. There is need to know the temperature asymmetry as it can cause tilting of the components. Experiments were carried out in an annulus model to predict the circumferential temperature difference with and without sodium in the test vessel. Three-dimensional analysis was also carried out using PHOENICS CFD code and compared with the experiment. This paper describes the experimental details, the theoretical analysis and their comparison. 相似文献
89.
Galiveeti Hemakumar Reddy Malepati Krishnmurthy Kiran Pulumithi Sunil Kumar Arup Kumar Goswami Nalin B. Dev Choudhury 《电力部件与系统》2019,47(19-20):1791-1804
AbstractThe equipment failures are highly uncertain in nature and simple average failure rate will not reflect this uncertainty. The uncertainty level further increases in reliability evaluation due to the integration of wind farm (WF) because of the intermittent nature of wind speed and random charging patterns of plug-in electric vehicles (PEVs). In this work, the uncertain variables in the distribution system (failure rate, repair time, WF output, PEVs charging and system load factor) are represented as fuzzy numbers to handle the uncertainty. The available uncertain data are used to find the probability distribution function (PDF) of that parameter and is converted into fuzzy membership function using transformation techniques. Failure rate of equipment is converted into failure probability using Monte Carlo simulation (MCS) method. Sampling method is applied to create the PDF of a variable which has average value. Fuzzy severity index (FSI) is proposed to find the importance of an equipment on reliability and is evaluated by measuring the fuzzy distance between the fuzzy reliability indices. The proposed assessment method is validated on modified RBTS bus 2 by comparing with analytical and MCS methods. The proposed method has been tested with integration of WFs and PEVs. 相似文献
90.
Jaideep J. Rao Kiran Kumar Ravulapati Tapas K. Das 《International journal of systems science》2013,44(12-13):717-730
Non-cooperative decision-making problems in a decentralized supply chain can be characterized and studied using a stochastic game model. In an earlier paper, the authors developed a methodology that uses machine learning for finding (near) optimal policies for non-zero sum stochastic games, and applied their methodology on an N-retailer and W-warehouse inventory-planning problem. The focus of this paper is on making the methodology more amenable to practical applications by making it completely simulation-based. It is also demonstrated, through numerical example problems, how this methodology can be used to find (near) equilibrium policies, and evaluate short-term rewards of stochastic games. Short-term rewards of stochastic games could be, in many instances, more critical than equilibrium rewards. To our knowledge, no methodology exists in the open literature that can capture the short-term behaviour of non-zero sum stochastic games as examined in this paper. 相似文献